1. Field of Technology
The present invention relates to an inkjet printing apparatus, recording head cleaning method, control process and computerized cleaning program for the recording head in a printer.
2. Description of Related Art
Inkjet printers that print by discharging ink from a recording head are widely available. This type of printer requires regular maintenance in order to maintain the reliability of the recording head. To prevent nozzle clogging and other printing problems resulting from ink drying and ink viscosity increasing inside the recording head nozzles, inkjet printers often have a mechanism for regularly cleaning the nozzles as shown in, for example, Japanese Unexamined Patent Appl. Pub. 2000-141686 (page 9 and FIG. 11).
Cleaning the recording head in a conventional inkjet printer is not limited to simply cleaning the nozzle port (by wiping or rubbing), and is more specifically directed to forcibly discharging ink that has increased in viscosity inside the nozzles, and to clearing bubbles that have grown in the ink path from the ink tank to the nozzles. In the cleaning process ink is vacuumed from the recording head. The cleaning operation consumes much ink, thus actually reducing the amount of usable ink inside the cartridge, increasing the frequency of cartridge replacement, and thus increasing the operating cost. The number of depleted cartridges (waste) thus increases, which is undesirable in terms of resource conservation and environmental protection.
The cleaning method taught in Japanese Unexamined Patent Appl. Pub. 2000-141686 provides timer cleaning for repeatedly cleaning the recording head at a regular interval in addition to manual cleaning which consumes a relatively large volume of ink and is used when the appropriate operator instruction is received. The cleaning method simply prevents manual cleaning from being used when the remaining ink level drops to a certain level. More particularly, this cleaning method does nothing to reduce ink consumption due to cleaning. More specifically, timer cleaning and manual cleaning simply consume different amounts of ink, and in neither cleaning mode is ink consumption reduced by adapting the cleaning process to the current condition of the printer.